Case Studies In this unit we are going to look at Solar Power, Energy and Transport and Wind energy.

Solar Power

Solar power can be harnesses for use in domestic products. Solar Cells (really called "photovoltaic" or "photoelectric" cells) that convert light directly into electricity. In a sunny climate, you can get enough power to run a 100W light bulb from just one square metre of solar panel. This was originally developed in order to provide electricity for satellites, but these days many of us own calculators powered by solar cells.

Solar water heating, where heat from the Sun is used to heat water in glass panels on your roof. This means you don't need to use so much gas or electricity to heat your water at home. Water is pumped through pipes in the panel. The pipes are painted black, so they get hot when the Sun shines on them.

Solar heating helps out your central heating system, and cuts your fuel bills. However, in the UK you must remember to drain the water out to stop the panels freezing in the winter. Solar heating is worthwhile in places like California and Australia, where you get lots of sunshine.

Advantages of solar power Solar energy is free - it needs no fuel and produces no waste or pollution. In sunny countries, solar power can be used where there is no easy way to get electricity to a remote place. Handy for low-power uses such as solar powered garden lights and battery chargers

Disadvantages of solar power Doesn't work at night. Very expensive to build solar power stations. Solar cells cost a great deal compared to the amount of electricity they'll produce in their lifetime. Can be unreliable unless you're in a very sunny climate. In the United Kingdom, solar power isn't much use except for low-power applications, as you need a very large area of solar panels to get a decent amount of power. However, for these applications it's definitely worthwhile.

Design of a solar cooker The three most common types of solar cookers are heat-trap boxes, curved concentrators (parabolic) and panel cookers. Hundreds — if not thousands — of variations on these basic types exist.

Solar Box cookers Box cookers cook at moderate to high temperatures and often accommodate multiple pots. Worldwide, they are the most widespread. There are several hundred thousand in India alone.

Solar curved concentrator cookers Curved concentrator cookers, or "parabolic," cook fast at high temperatures, but require frequent adjustment and supervision for safe operation. Several hundred thousand exist, mainly in China. They are especially useful for large-scale institutional cooking.

Solar panel cookers Panel cookers incorporate elements of box and curved concentrator cookers. They are simple and relatively inexpensive to buy or produce. Solar Cookers International's "CooKit" is the most widely used combination cooker.

Solar cooking is the simplest, safest, most convenient way to cook food without consuming fuels or heating up the kitchen. Many people choose to solar cook for these reasons. But for hundreds of millions of people around the world who cook over fires fuelled by wood or dung, and who walk for miles to collect wood or spend much of their meagre incomes on fuel, solar cooking is more than a choice — it is a blessing. Solar cookers as sustainable development

Food is easily and conveniently cooked with solar energy as the "fuel" in solar cookers (or solar ovens). Solar cookers are an ideal addition to any kitchen wherever there are predictable hours of sun many days of the year. Solar cooking and baking are easy. Solar cookers are safe around children and provide a great way to learn about and use solar energy.

Solar cookers as sustainable development In some rural areas, for example, Nepal, traditional cooking methods involve the burning of biomass fuels and result in indoor air pollution, which is one of the four most critical environmental problems in developing countries.

Solar cookers as sustainable development Women and children are more likely to be exposed to indoor air pollution as many women in developing countries spend hours per day cooking near an open fire often with a child strapped to their back.

Solar cookers as sustainable development Indoor air pollution can damage lungs, contributing to acute lower respiratory infections, chronic lung disease, lung cancer, asthma, low birth weight and heart disease.

Solar cookers as sustainable development Collection of wood and other biomass fuels contributes to deforestation, with impacts on the water table.

Solar Cookers Solar cookers are clean, convenient, non- polluting and easy on the environment. And, for millions of people living in arid, fuel-scarce regions of the world, solar cookers can literally save lives.

Energy and Transport

Individual Transport Systems Individual Cars Taxis Motorbikes Individual transport systems often cause congestion and increased pollution. The only method of individual transport that promotes sustainable development is the bike.

Mass Transport Systems Trains Airplanes Boats Buses Mass transport systems move more people, which means less pollution then individual transport systems. Mass transport systems can be designed to promote sustainable development, but this is still in development.

Making the change There are many barriers to transition from individual cars to mass public transportation. Convenience Flexibility Systems Integration (Park and Ride)

Convenience The public want transport to be convenient. In groups of 2 or 3 discuss what is convenient and inconvenient about having your own car In groups of 2 or 3 discuss what is convenient and inconvenient about travelling by bus.

Flexibility The public want transport to be flexible. In groups of 3 or 3 discuss the flexibility in mass transport systems. In groups of 3 or 3 discuss the flexibility in individual transport systems.

Systems Integration Some local councils in the UK have tried to find a happy medium and have introduced a system called park and ride. Cambridge, England Park & Ride allows commuters, coming into Cambridge, to enjoy stress free travel and beat the queues. It also allows visitors and shoppers to take the direct route to the heart of the city. Parking is Free!

Systems Integration Discuss the park and ride in Jakarta. How could this system work in Indonesia?

Wind Energy

Small scale wind farms Advantages No danger to birds Good source of energy for isolated houses Cheap to install Disadvantages Not useful in urban setting

Large scale wind farms Advantages Clean source of energy Farmland can be used for grazing and generating energy Can feed into the national grid Disadvantages Kills birds Expensive to install Eyesore on the landscape

Locations of large wind farms Onshore Offshore

Locations of large wind farms There are many issues associated with the location of large scale wind farms: Noise pollution Visual pollution Community lobbying: NIMBY (not in my back yard) Costs of development Onshore and offshore developments Damage to flying wildlife